feat(check-plugin): apply fixes flag

Add --fix / -x which automatically applies go.mod fixes instead of
just printing them out.

go.mod

@@ -11,7 +11,7 @@ require (
 	github.com/santhosh-tekuri/jsonschema/v5 v5.0.0
 	github.com/spf13/cobra v1.1.3
 	github.com/stretchr/testify v1.9.0
-	golang.org/x/mod v0.12.0
+	golang.org/x/mod v0.19.0
 )
 
 require (

go.sum

@@ -605,8 +605,8 @@ golang.org/x/mod v0.4.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.1/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
 golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
-golang.org/x/mod v0.12.0 h1:rmsUpXtvNzj340zd98LZ4KntptpfRHwpFOHG188oHXc=
-golang.org/x/mod v0.12.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/mod v0.19.0 h1:fEdghXQSo20giMthA7cd28ZC+jts4amQ3YMXiP5oMQ8=
+golang.org/x/mod v0.19.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20181023162649-9b4f9f5ad519/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=

plugin.go

@@ -10,18 +10,22 @@ import (
 	"golang.org/x/mod/modfile"
 )
 
-// indirectRequires returns the indirect dependencies of the go.sum file.
-func indirectRequires(goSum string) (map[string]struct{}, error) {
-	dir := filepath.Dir(goSum)
-	filename := filepath.Join(dir, "go.mod")
+// goMod returns the go.mod file path from the go.sum file path.
+func goMod(goSum string) string {
+	return filepath.Join(filepath.Dir(goSum), "go.mod")
+}
+
+// indirectRequires returns the details and indirect dependencies of the go.sum file.
+func indirectRequires(goSum string) (*modfile.File, map[string]struct{}, error) {
+	filename := goMod(goSum)
 	data, err := os.ReadFile(filename)
 	if err != nil {
-		return nil, fmt.Errorf("reading go.mod: %w", err)
+		return nil, nil, fmt.Errorf("read go.mod: %w", err)
 	}
 
 	f, err := modfile.Parse(filename, data, nil)
 	if err != nil {
-		return nil, fmt.Errorf("parsing go.mod: %w", err)
+		return nil, nil, fmt.Errorf("parse go.mod: %w", err)
 	}
 
 	indirects := map[string]struct{}{}
@@ -31,7 +35,23 @@ func indirectRequires(goSum string) (map[string]struct{}, error) {
 		}
 	}
 
-	return indirects, nil
+	return f, indirects, nil
+}
+
+// writeModFile writes the modfile.File to the go.mod file determined from goSum.
+func writeModFile(goSum string, f *modfile.File) error {
+	f.Cleanup()
+	data, err := f.Format()
+	if err != nil {
+		return fmt.Errorf("format go.mod: %w", err)
+	}
+
+	filename := goMod(goSum)
+	if err = os.WriteFile(filename, data, 0644); err != nil {
+		return fmt.Errorf("write go.sum: %w", err)
+	}
+
+	return nil
 }
 
 // getBuildInfo returns the dependencies of the binary calling it.
@@ -66,32 +86,86 @@ func pluginFuncErr(cmd *cobra.Command, _ []string) error {
 		return nil
 	}
 
-	if gogetEnabled {
-		indirects, err := indirectRequires(goSum)
-		if err != nil {
+	var indirects map[string]struct{}
+	var modFile *modfile.File
+	if gogetEnabled || fixEnabled {
+		if modFile, indirects, err = indirectRequires(goSum); err != nil {
 			return err
 		}
-		for _, diff := range diffs {
-			if diff.Name != "go" && diff.Name != "libc" {
-				if _, ok := indirects[diff.Name]; ok {
-					cmd.Printf("go mod edit --replace %s=%s@%s\n", diff.Name, diff.Name, diff.Expected)
-				} else {
-					cmd.Printf("go get %s@%s\n", diff.Name, diff.Expected)
-				}
-				continue
+	}
+
+	fixed, err := outputOrFix(cmd, diffs, modFile, indirects)
+	if err != nil {
+		return err
+	}
+
+	// Report any remaining incompatibilities.
+	if len(diffs) != fixed {
+		if fixed > 0 {
+			return fmt.Errorf("%d incompatibilities fixed, %d left", fixed, len(diffs)-fixed)
+		}
+
+		return fmt.Errorf("%d incompatibilities found", len(diffs))
+	}
+
+	return nil
+}
+
+// outputOrFix prints the incompatibilities or applies the fixes if fixEnabled is true.
+// It returns the number of incompatibilities fixed.
+func outputOrFix(cmd *cobra.Command, diffs []plugin.Diff, modFile *modfile.File, indirects map[string]struct{}) (int, error) {
+	var fixed int
+	for _, diff := range diffs {
+		if diff.Name != "go" && diff.Name != "libc" && (gogetEnabled || fixEnabled) {
+			if ok, err := outputOrFixDiff(cmd, diff, modFile, indirects); err != nil {
+				return 0, err
+			} else if ok {
+				fixed++
 			}
+			continue
+		}
+
+		cmd.Println(diff.Name)
+		cmd.Println("\thave:", diff.Have)
+		cmd.Println("\twant:", diff.Expected)
+	}
+
+	if fixed > 0 {
+		if err := writeModFile(goSum, modFile); err != nil {
+			return 0, err
+		}
+
+		cmd.Printf("%d incompatibilities fixed\n", fixed)
+	}
+
+	return fixed, nil
+}
 
-			cmd.Println(diff.Name)
-			cmd.Println("\thave:", diff.Have)
-			cmd.Println("\twant:", diff.Expected)
+// outputOrFixDiff prints the commands to fix the incompatibility or applies
+// the fix if fixEnabled is true for the given diff.
+// It returns true if the incompatibility was fixed.
+func outputOrFixDiff(cmd *cobra.Command, diff plugin.Diff, modFile *modfile.File, indirects map[string]struct{}) (bool, error) {
+	if _, ok := indirects[diff.Name]; ok {
+		if fixEnabled {
+			if err := modFile.AddReplace(diff.Name, "", diff.Name, diff.Expected); err != nil {
+				return false, fmt.Errorf("add replace: %w", err)
+			}
+			return true, nil
 		}
-	} else {
-		for _, diff := range diffs {
-			cmd.Println(diff.Name)
-			cmd.Println("\thave:", diff.Have)
-			cmd.Println("\twant:", diff.Expected)
+
+		cmd.Printf("go mod edit --replace %s=%s@%s\n", diff.Name, diff.Name, diff.Expected)
+
+		return false, nil
+	}
+
+	if fixEnabled {
+		if err := modFile.AddRequire(diff.Name, diff.Expected); err != nil {
+			return false, fmt.Errorf("add require: %w", err)
 		}
+
+		return true, nil
 	}
+	cmd.Printf("go get %s@%s\n", diff.Name, diff.Expected)
 
-	return fmt.Errorf("%d incompatibilities found", len(diffs))
+	return false, nil
 }

plugin_test.go

@@ -2,22 +2,60 @@ package cmd
 
 import (
 	"bytes"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
 	"testing"
 
 	"github.com/krakendio/krakend-cobra/v2/plugin"
+	"github.com/luraproject/lura/v2/core"
 	"github.com/spf13/cobra"
 	"github.com/stretchr/testify/require"
 )
 
+const testDir = "testdata"
+
+// copyDir is a helper function to copy directory entries from src to dst.
+func copyDir(t *testing.T, srcSubDir, dstDir string) {
+	t.Helper()
+
+	srcDir := filepath.Join(testDir, srcSubDir)
+	entries, err := os.ReadDir(srcDir)
+	if errors.Is(err, os.ErrNotExist) {
+		// Nothing to do.
+		return
+	}
+	require.NoError(t, err)
+
+	for _, entry := range entries {
+		file := entry.Name()
+		data, err := os.ReadFile(filepath.Join(srcDir, file))
+		require.NoError(t, err)
+
+		err = os.WriteFile(filepath.Join(dstDir, file), data, 0644)
+		require.NoError(t, err)
+	}
+}
+
+// loadFile is a helper function to load a file from the testdata directory.
+func loadFile(t *testing.T, name string) string {
+	t.Helper()
+	data, err := os.ReadFile(filepath.Join(testDir, name))
+	require.NoError(t, err)
+
+	return string(data)
+}
+
 func Test_pluginFuncErr(t *testing.T) {
 	var buf bytes.Buffer
 	cmd := &cobra.Command{}
 	cmd.SetOutput(&buf)
 
 	localDescriber = func() plugin.Descriptor {
 		return plugin.Descriptor{
-			Go:   goVersion,
-			Libc: libcVersion,
+			Go:   core.GoVersion,
+			Libc: core.GlibcVersion,
 			Deps: map[string]string{
 				"golang.org/x/mod":                  "v0.6.0-dev.0.20220419223038-86c51ed26bb4",
 				"github.com/Azure/azure-sdk-for-go": "v59.3.0+incompatible",
@@ -28,63 +66,105 @@ func Test_pluginFuncErr(t *testing.T) {
 
 	defer func() { localDescriber = plugin.Local }()
 
+	goModData := loadFile(t, "go.mod")
+
 	tests := map[string]struct {
-		goSum    string
-		expected string
-		fix      bool
-		err      string
+		dir           string
+		expected      string
+		expectedGoMod string
+		goVersion     string
+		format        bool
+		fix           bool
+		err           string
 	}{
+
 		"missing": {
-			goSum: "./testdata/missing-go.sum",
-			err:   "open ./testdata/missing-go.sum: no such file or directory",
+			dir:           "missing",
+			goVersion:     goVersion,
+			expectedGoMod: goModData,
+			err:           "open DIR/go.sum: no such file or directory",
 		},
-		"matching": {
-			goSum:    "./testdata/match-go.sum",
-			expected: "No incompatibilities found!\n",
+
+		"match": {
+			dir:           "match",
+			goVersion:     goVersion,
+			expectedGoMod: goModData,
+			expected:      "No incompatibilities found!\n",
 		},
 		"changes": {
-			goSum: "./testdata/changes-go.sum",
-			expected: `cloud.google.com/go
-	have: v0.100.3
-	want: v0.100.2
-github.com/Azure/azure-sdk-for-go
-	have: v59.3.1+incompatible
-	want: v59.3.0+incompatible
-golang.org/x/mod
-	have: v0.6.10-dev.0.20220419223038-86c51ed26bb4
-	want: v0.6.0-dev.0.20220419223038-86c51ed26bb4
-`,
-			err: "3 incompatibilities found",
+			dir:           "changes",
+			goVersion:     goVersion,
+			expectedGoMod: goModData,
+			expected:      loadFile(t, "changes/expected.txt"),
+			err:           "3 incompatibilities found",
 		},
-		"fix": {
-			goSum: "./testdata/changes-go.sum",
-			fix:   true,
-			expected: `go mod edit --replace cloud.google.com/go=cloud.google.com/go@v0.100.2
-go mod edit --replace github.com/Azure/azure-sdk-for-go=github.com/Azure/azure-sdk-for-go@v59.3.0+incompatible
-go get golang.org/x/mod@v0.6.0-dev.0.20220419223038-86c51ed26bb4
+		"format": {
+			dir:           "changes",
+			goVersion:     goVersion,
+			expectedGoMod: goModData,
+			format:        true,
+			expected:      loadFile(t, "format/expected.txt"),
+			err:           "3 incompatibilities found",
+		},
+		"fixed-all": {
+			dir:           "changes",
+			goVersion:     goVersion,
+			expectedGoMod: loadFile(t, "fixed-all/go.mod"),
+			fix:           true,
+			expected:      "3 incompatibilities fixed\n",
+		},
+		"fixed-some": {
+			dir:           "changes",
+			goVersion:     "1.1.0",
+			expectedGoMod: loadFile(t, "fixed-some/go.mod"),
+			fix:           true,
+			expected: `go
+	have: 1.1.0
+	want: undefined
+3 incompatibilities fixed
 `,
-			err: "3 incompatibilities found",
+			err: "3 incompatibilities fixed, 1 left",
 		},
 	}
 	for name, tc := range tests {
 		t.Run(name, func(t *testing.T) {
 			buf.Reset()
 
+			// Make copies in a temporary directory so
+			// the original files are not modified.
+			tempDir := t.TempDir()
 			orig := goSum
-			goSum = tc.goSum
+			goSum = filepath.Join(tempDir, "go.sum")
+			copyDir(t, tc.dir, tempDir)
 			defer func() { goSum = orig }()
 
-			fix := gogetEnabled
-			gogetEnabled = tc.fix
-			defer func() { gogetEnabled = fix }()
+			// Override the global variables for the test.
+			format := gogetEnabled
+			fix := fixEnabled
+			gogetEnabled = tc.format
+			fixEnabled = tc.fix
+			oldGoVersion := goVersion
+			goVersion = tc.goVersion
+			defer func() {
+				gogetEnabled = format
+				fixEnabled = fix
+				goVersion = oldGoVersion
+			}()
 
 			err := pluginFuncErr(cmd, nil)
 			if tc.err != "" {
-				require.EqualError(t, err, tc.err)
+				require.EqualError(t, err, strings.ReplaceAll(tc.err, "DIR", tempDir))
 			} else {
 				require.NoError(t, err)
 			}
 			require.Equal(t, tc.expected, buf.String())
+
+			data, err := os.ReadFile(filepath.Join(tempDir, "go.mod"))
+			if errors.Is(err, os.ErrNotExist) {
+				return
+			}
+			require.NoError(t, err)
+			require.Equal(t, string(tc.expectedGoMod), string(data))
 		})
 	}
 }